So I went to the store to buy oil to break in a rotary motor. Bought straight 30W oil. That was what I was told. I thought you could put in any 10-30W and call it a day. At least that was what was in my car the previous two motors I did in 20++ years...

They also sold me engine break in additive (Lucas) which I thought was useless. Said something on it about cams and lifters. LOL.

Wasted money right?

Thoughts?

 

Depends on what was replaced in the engine at rebuild time, if non of the bearing were replaced then you can use anything you like, if bearing were done then a 20 or 30 weight is good for the first 1000km's

 

I have used Shell Rotella T 15W40 Diesel engine oil for years in all my new engines, never had any bearing failures or oil related problems since using that oil with brand new bearings.

I'd recommend that oil to anyone street driving any Rotary engine car.

A lot of top name piston engine builders use that exact same oil on engine break-in for bearings and cams.

 

It's oil, just make sure its in there and is changed after breakin since itll be dirtier then normal.

thewird

 

I think you should have bought the Lucas additive, everyone knows the cams are a weak point on the rotary :P

-Geoff

 

Gotta love that zinc baby. I have heard the same comments from a number of places. Break in with the Shell Rotella Diesel oil, then convert to the synthetic you are going to use for the regular racing. I wonder if the Break In additive would help the rotard bearings a bit more during break in as well?

Eric

 

People who think "its just oil" need to re-evaluate being a mechanic on other peoples cars.

 

Joe, you should know better then anyone that everyone has their own opinions. I respect yours as I would expect you to respect mine. If that is what you think, that is your opinion.

But since you brought it up, I think their are more important things that goes into making an engine live then what type of oil you use during the period of the motors life when it shouldn't be under any hard load at all. I'd want the new bearings to scuff their high spots so it'll break in faster, not protect them. It's also noteworthy that Mazda does not break-in any engine in any car they sell and the owners would generally punch it coming out of the dealership on 10w30 or 5w20 (rx8) with all brand new parts and the motors still go 200,000+ km unless they blow which is unrelated to any oil issue. I've never heard of a new (not reman) motor from the dealer spinning a bearing.

I'm also of the opinion if a bearing is spun its because something was wrong in the first place.

thewird

 

Thanks guys for the opinion. Going to return my 30 weight and lucss additive and use a 10W-30 for breakin. Just like I did in the past.